From that, here are the 2 guys we might have a shot at.
We need a safety.
Some say Morgan Burnett is better NOT being the free safety. Perhaps since it's better if he just misses tackles nearer the LOS than allowing touchdown passes on the back end.
If that's the case, we probably want the kid with the funny name as he looks like a faster glider back there.
But if we want to get more physical, I think CP25 is our guy. Better chance he's available.

Again, these quotes are from this link, where you can read 48 more. This is just a 4% snippet of the free material available there, of the 2 guys I hope we take one of at #21.

34. Calvin Pryor
S; Junior; Louisville; 6-2, 208

The hunt for the next Kam Chancellor continues with Pryor, who earned a reputation at Louisville as a ferocious hitter who could knock an opposing receiver out of the game with a clean shot. Pryor has excellent instincts, and those hits usually aren’t attempts at highlight-reel plays. They’re usually fundamentally sound tackles that happen to rattle the ballcarrier’s fillings.

19. Ha Ha Clinton-Dix
S; Junior; Alabama; 6-1, 208

Clinton-Dix is the most complete safety prospect in the draft. He can run, he can cover, and he can lay the wood.